Word line repair for 3D vertical channel memory

Abstract

A memory device includes a plurality of stacks of conductive strips alternating with insulating strips, including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, a top plane of conductive strips, and an additional intermediate plane. A plurality of vertical structures is arranged orthogonally to the plurality of stacks. Memory elements are disposed in interface regions at cross-points between side surfaces of the plurality of stacks and the plurality of vertical structures. A stack of linking elements is connected to conductive strips in respective intermediate planes and to the additional intermediate plane. Decoding circuitry is coupled to the plurality of intermediate planes and the additional intermediate plane, and is configured to replace an intermediate plane indicated to be defective with the additional intermediate plane.

What is claimed is:  
     
       1. A memory device, comprising:
 a plurality of stacks of conductive strips alternating with insulating strips, including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, a top plane of conductive strips, and an additional intermediate plane of conductive strips; 
 a plurality of vertical structures arranged orthogonally to the plurality of stacks; 
 memory elements in interface regions at cross-points between side surfaces of the plurality of stacks and the plurality of vertical structures; 
 a stack of linking elements separated by insulating layers, and connected to conductive strips in respective intermediate planes in the plurality of intermediate planes and to the additional intermediate plane; and 
 decoding circuitry coupled to the plurality of intermediate planes and the additional intermediate plane, and configured to replace an intermediate plane indicated to be defective with the additional intermediate plane. 
 
     
     
       2. The memory device of  claim 1 , wherein the decoding circuitry includes a memory storing data that indicates whether a particular intermediate plane is defective, and logic to select the additional intermediate plane in response to said data. 
     
     
       3. The memory device of  claim 1 , comprising a plurality of additional intermediate planes. 
     
     
       4. The memory device of  claim 3 , wherein the plurality of additional intermediate planes is disposed between the top plane of conductive strips and the plurality of intermediate planes. 
     
     
       5. The memory device of  claim 3 , wherein the plurality of additional intermediate planes is disposed between the plurality of intermediate planes and the bottom plane of conductive strips. 
     
     
       6. The memory device of  claim 1 , including a plurality of pairs of interlayer connectors extending from a connector surface, wherein each pair of interlayer connectors includes redundant first and second interlayer connectors connected to a single linking element in the stack of linking elements. 
     
     
       7. The memory device of  claim 6 , including patterned conductor lines on top of the connector surface, connected to respective pairs of interlayer connectors, and coupled to the decoding circuitry. 
     
     
       8. The memory device of  claim 1 , comprising:
 a pair of interlayer connectors extending from a second connector surface to a linking element connected to conductive strips in the bottom plane. 
 
     
     
       9. The memory device of  claim 8 , comprising:
 a patterned conductor line on top of the second connector surface, connected to the pair of interlayer connectors, and coupled to second decoding circuitry coupled to the bottom plane. 
 
     
     
       10. The memory device of  claim 1 , comprising blocks of stacks of conductive strips, each block including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, a top plane of conductive strips, and an additional intermediate plane of conductive strips,
 wherein the decoding circuitry is configured to replace an intermediate plane indicated to be defective in a particular block with the additional intermediate plane in the particular block. 
 
     
     
       11. A method for manufacturing a memory device, comprising:
 forming a plurality of conductive layers alternating with insulating layers on a substrate; 
 forming an array of vertical structures extending through the plurality of conductive layers; 
 etching the plurality of conductive layers to define a plurality of stacks of conductive strips alternating with insulating strips, including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, a top plane of conductive strips, and an additional intermediate plane of conductive strips; 
 forming memory elements in interface regions at cross-points between side surfaces of the plurality of stacks and the array of vertical structures; 
 defining a stack of linking elements separated by insulating layers, and connected to conductive strips in respective intermediate planes in the plurality of intermediate planes and to the additional intermediate plane; 
 forming bit lines and structures to connect the array of vertical structures to the bit lines; and 
 providing decoding circuitry coupled to the plurality of intermediate planes and the additional intermediate plane configured to replace an intermediate plane indicated to be defective with the additional intermediate plane. 
 
     
     
       12. The method of  claim 11 , wherein the decoding circuitry includes a memory storing data that indicates whether a particular intermediate plane is defective, and logic to select the additional intermediate plane in response to said data. 
     
     
       13. The method of  claim 11 , the plurality of stacks of conductive strips including a plurality of additional intermediate planes. 
     
     
       14. The method of  claim 13 , wherein the plurality of additional intermediate planes is disposed between the top plane of conductive strips and the plurality of intermediate planes. 
     
     
       15. The method of  claim 13 , wherein the plurality of additional intermediate planes is disposed between the plurality of intermediate planes and the bottom plane of conductive strips. 
     
     
       16. The method of  claim 11 , including forming a plurality of pairs of interlayer connectors extending from a connector surface, wherein each pair of interlayer connectors includes redundant first and second interlayer connectors connected to a single linking element in the stack of linking elements. 
     
     
       17. The method of  claim 16 , including forming patterned conductor lines on top of the connector surface, connected to respective pairs of interlayer connectors, and coupled to the decoding circuitry. 
     
     
       18. The method of  claim 11 , including forming a pair of interlayer connectors extending from a second connector surface to a linking element connected to conductive strips in the bottom plane. 
     
     
       19. The method of  claim 18 , including forming a patterned conductor line on top of the second connector surface, connected to the pair of interlayer connectors, and coupled to second decoding circuitry coupled to the bottom plane. 
     
     
       20. The method of  claim 11 , wherein the memory device comprises blocks of stacks of conductive strips, each block including at least a bottom plane of conductive strips, a plurality of intermediate planes of conductive strips, a top plane of conductive strips, and an additional intermediate plane of conductive strips, and the decoding circuitry is configured to replace an intermediate plane indicated to be defective in a particular block with the additional intermediate plane in the particular block.